First Taiwanese reactor to enter decommissioning

05 December 2018

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Taiwan Power Company (Taipower) said it plans to decommission unit 1 of its Chinshan nuclear power plant following the expiration of the reactor's operating licence today after 40 years of operation. However, the utility must first be granted a decommissioning permit before work can begin.

Chinshan units 1 and 2 (Image: Taipower)

Taipower announced that the operating licence of Chinshan 1 - a 636 MWe boiling water reactor that was commissioned in December 1978 - expired today. The unit has been idle for almost three years following a fuel fault which has been rectified. Despite having regulatory approval to operate, its restart has been blocked politically. Taipower said Chinshan 1 will officially cease operation and enter the decommissioning stage tomorrow. The unit has produced some 162.5 TWh of electricity since it started up, the utility noted. It becomes the first Taiwanese power reactor to enter decommissioning.

Under Taiwanese regulations, a decommissioning plan for a power reactor must be submitted by the licensee three years prior to its scheduled permanent shut down. The decommissioning shall be completed within 25 years upon obtaining a decommissioning permit from the regulator.

Taipower's decommissioning plan for Chinshan 1 was approved by the Atomic Energy Commission (AEC) on 28 June 2017. The utility submitted an environmental impact assessment (EIA), which covers the disposal of used fuel and other materials - to the Environmental Protection Administration in January 2016 for review and approval. The decommissioning permit for Chinshan 1 will be granted by the AEC once the EIA is approved.

The plan to decommission Chinshan 1 - together with unit 2, whose operating licence will expire on 15 July next year - includes the construction of a dry storage facility for used fuel. Construction of this facility was completed in 2013. However, the New Taipei City municipal government has yet to issue a permit for its use. Decommissioning of the unit cannot begin until all 816 fuels rods have been removed from its reactor core and the used fuel pool.

Taipower's plans for decommissioning Chinshan 1 comprise four stages.

During the initial "post-operation transition" period - expected to take eight years - used fuel will be transferred from the reactor core to the used fuel storage pool. A survey will be carried out to characterise the site and engineering planning will be conducted. In addition, the reactor cooling systems will be drained and decontaminated. During this period, an independent spent fuel storage installation (ISFSI) and a radioactive waste storage area will be established.

In the second stage - the decontamination and dismantling phase - used fuel will be moved to the ISFSI. The reactor pressure vessel and internals will be dismantled, together with the reactor cooling system pipework. The used fuel storage pool will also be dismantled, together with the primary containment structure. Decontamination of the concrete and buildings will also be carried out. Large components in the turbine building will be dismantled. This work is expected to take 12 years to complete.

In the third stage, expected to last three years, the reactor building and turbine building will be demolished and a final site survey conducted.

In the final site recovery stage - scheduled to be completed by the end of 2043 - other buildings will be demolished and the site restored.

Taiwan's Democratic Progressive Party (DPP) was elected to government in January 2016 having a policy of creating a "nuclear-free homeland" by 2025. Under this policy, Taiwan's six operable power reactors will be decommissioned as their 40-year operating licences expire. Shortly after taking office, the DPP government passed an amendment to the Electricity Act, passing its phase-out policy into law.

However, in a referendum held late last month, voters chose to abolish that amendment.

Construction of two units at Lungmen began in 1999, but the project has been beset with political, legal and regulatory delays. The completed unit 1 was mothballed in July 2015, while construction of unit 2 was suspended in April 2014.